“Prostate-specific antigen (PSA) levels are significantly lower in aspirin users with latent prostate cancer than in similar patients who are not aspirin users,” say Vanderbilt University “scientists who caution that aspirin may affect prostate cancer detection.”
Published data from the Prostate Cancer Prevention Trial demonstrated that there is no PSA level below which the risk of having prostate cancer is zero. For an individual patient, the significance of a PSA level should be interpreted in a broad clinical context, including age, race, family history, digital rectal exam, prostate size, results of prior prostate biopsy, and use of 5α-reductase inhibitors. Considering the high incidence of asymptomatic cancer in the general population that may not pose an ultimate risk to the patient, the decision to recommend urological evaluation or prostate biopsy should be individualized after considering all these factors.
The risk that a patient will have prostate cancer detected if a biopsy is performed at various levels of PSA is listed in the table below:
PSA Relative risk for prostate cancer
| PSA | Relative risk for prostate cancer |
| ≤1.0 ng/mL | 8.8% |
| 1.1-2.0 ng/mL | 17% |
| 2.1-3.0 ng/mL | 23.9% |
| 3.1-4.0 ng/mL | 26.9% |
| >4 ng/mL | 45.5% |
The U.S. Preventive Services Task Force recently recommended that men age 75 years and older and men under age 75 with chronic medical problems and a life expectancy of fewer than 10 years not be screened for prostate caner (Ann Intern Med 2008; 149:185-91). This report received a lot of attention in the lay press; however, it is not new. Most in the urologic community have been making this same recommendation for the last 20 years. The key word here is screening. Screening specifically refers to asymptomatic men without significant risk factors for prostate cancer. Only about 10% of men older than 75 years will die of cancer and only 9% of men age 85 or older can expect to live 10 years or longer. This recommendation does not mean that men with a suspicious digital rectal exam, or significant new or continued voiding problems, should not have their PSA checked.